add workaround for agent_schedule bug

[lowlydba]

Description

Add a workaround to manually refresh the agent schedule.

How Has This Been Tested?

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue) - Fixes #184
• [ ] New feature (non-breaking change which adds functionality)

Checklist:

• [x] I have read/followed the CONTRIBUTING document.
• [x] I have read/followed the PR Quick Start Guide
• [x] I have added tests to cover my changes or they are N/A.
• [x] I have added a changelog fragment describing the changes.
• [x] New module options/parameters include a version_added property.

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: +4.27 :tada:

Comparison is base (620daa3) 89.52% compared to head (9fcf266) 93.79%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #185 +/- ## ========================================== + Coverage 89.52% 93.79% +4.27% ========================================== Files 52 64 +12 Lines 1441 2192 +751 ========================================== + Hits 1290 2056 +766 + Misses 151 136 -15 ``` | Flag | Coverage Δ | | |---|---|---| | sanity | `100.00% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=John+McCall#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://app.codecov.io/gh/lowlydba/lowlydba.sqlserver/pull/185?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=John+McCall) | Coverage Δ | | |---|---|---| | [plugins/modules/agent\_job\_schedule.ps1](https://app.codecov.io/gh/lowlydba/lowlydba.sqlserver/pull/185?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=John+McCall#diff-cGx1Z2lucy9tb2R1bGVzL2FnZW50X2pvYl9zY2hlZHVsZS5wczE=) | `98.16% <100.00%> (ø)` | | ... and [14 files with indirect coverage changes](https://app.codecov.io/gh/lowlydba/lowlydba.sqlserver/pull/185/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=John+McCall)

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